[ConstantRange] Add isWrappedSet() and isUpperSignWrapped()

Split off from D59749. This adds isWrappedSet() and
isUpperSignWrapped() set with the same behavior as isSignWrappedSet()
and isUpperWrapped() for the respectively other domain.

The methods isWrappedSet() and isSignWrappedSet() will not consider
ranges of the form [X, Max] == [X, 0) and [X, SignedMax] == [X, SignedMin)
to be wrapping, while isUpperWrapped() and isUpperSignWrapped() will.

Also replace the checks in getUnsignedMin() and friends with method
calls that implement the same logic.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@357112 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/IR/ConstantRange.h

@@ -163,6 +163,12 @@ public:
   /// Return true if this set contains no members.
   bool isEmptySet() const;
 
+  /// Return true if this set wraps around the unsigned domain. Special cases:
+  ///  * Empty set: Not wrapped.
+  ///  * Full set: Not wrapped.
+  ///  * [X, 0) == [X, Max]: Not wrapped.
+  bool isWrappedSet() const;
+
   /// Return true if the exclusive upper bound wraps around the unsigned
   /// domain. Special cases:
   ///  * Empty set: Not wrapped.
@@ -176,6 +182,13 @@ public:
   ///  * [X, SignedMin) == [X, SignedMax]: Not wrapped.
   bool isSignWrappedSet() const;
 
+  /// Return true if the (exclusive) upper bound wraps around the signed
+  /// domain. Special cases:
+  ///  * Empty set: Not wrapped.
+  ///  * Full set: Not wrapped.
+  ///  * [X, SignedMin): Wrapped.
+  bool isUpperSignWrapped() const;
+
   /// Return true if the specified value is in the set.
   bool contains(const APInt &Val) const;
 

lib/IR/ConstantRange.cpp

@@ -344,6 +344,10 @@ bool ConstantRange::isEmptySet() const {
   return Lower == Upper && Lower.isMinValue();
 }
 
+bool ConstantRange::isWrappedSet() const {
+  return Lower.ugt(Upper) && !Upper.isNullValue();
+}
+
 bool ConstantRange::isUpperWrapped() const {
   return Lower.ugt(Upper);
 }
@@ -352,6 +356,10 @@ bool ConstantRange::isSignWrappedSet() const {
   return Lower.sgt(Upper) && !Upper.isMinSignedValue();
 }
 
+bool ConstantRange::isUpperSignWrapped() const {
+  return Lower.sgt(Upper);
+}
+
 APInt ConstantRange::getSetSize() const {
   if (isFullSet())
     return APInt::getOneBitSet(getBitWidth()+1, getBitWidth());
@@ -388,19 +396,19 @@ APInt ConstantRange::getUnsignedMax() const {
 }
 
 APInt ConstantRange::getUnsignedMin() const {
-  if (isFullSet() || (isUpperWrapped() && !getUpper().isNullValue()))
+  if (isFullSet() || isWrappedSet())
     return APInt::getMinValue(getBitWidth());
   return getLower();
 }
 
 APInt ConstantRange::getSignedMax() const {
-  if (isFullSet() || Lower.sgt(Upper))
+  if (isFullSet() || isUpperSignWrapped())
     return APInt::getSignedMaxValue(getBitWidth());
   return getUpper() - 1;
 }
 
 APInt ConstantRange::getSignedMin() const {
-  if (isFullSet() || (Lower.sgt(Upper) && !getUpper().isMinSignedValue()))
+  if (isFullSet() || isSignWrappedSet())
     return APInt::getSignedMinValue(getBitWidth());
   return getLower();
 }

unittests/IR/ConstantRangeTest.cpp

@@ -35,7 +35,7 @@ TEST_F(ConstantRangeTest, Basics) {
   EXPECT_TRUE(Full.isFullSet());
   EXPECT_FALSE(Full.isEmptySet());
   EXPECT_TRUE(Full.inverse().isEmptySet());
-  EXPECT_FALSE(Full.isUpperWrapped());
+  EXPECT_FALSE(Full.isWrappedSet());
   EXPECT_TRUE(Full.contains(APInt(16, 0x0)));
   EXPECT_TRUE(Full.contains(APInt(16, 0x9)));
   EXPECT_TRUE(Full.contains(APInt(16, 0xa)));
@@ -45,7 +45,7 @@ TEST_F(ConstantRangeTest, Basics) {
   EXPECT_FALSE(Empty.isFullSet());
   EXPECT_TRUE(Empty.isEmptySet());
   EXPECT_TRUE(Empty.inverse().isFullSet());
-  EXPECT_FALSE(Empty.isUpperWrapped());
+  EXPECT_FALSE(Empty.isWrappedSet());
   EXPECT_FALSE(Empty.contains(APInt(16, 0x0)));
   EXPECT_FALSE(Empty.contains(APInt(16, 0x9)));
   EXPECT_FALSE(Empty.contains(APInt(16, 0xa)));
@@ -54,7 +54,7 @@ TEST_F(ConstantRangeTest, Basics) {
 
   EXPECT_FALSE(One.isFullSet());
   EXPECT_FALSE(One.isEmptySet());
-  EXPECT_FALSE(One.isUpperWrapped());
+  EXPECT_FALSE(One.isWrappedSet());
   EXPECT_FALSE(One.contains(APInt(16, 0x0)));
   EXPECT_FALSE(One.contains(APInt(16, 0x9)));
   EXPECT_TRUE(One.contains(APInt(16, 0xa)));
@@ -64,7 +64,7 @@ TEST_F(ConstantRangeTest, Basics) {
 
   EXPECT_FALSE(Some.isFullSet());
   EXPECT_FALSE(Some.isEmptySet());
-  EXPECT_FALSE(Some.isUpperWrapped());
+  EXPECT_FALSE(Some.isWrappedSet());
   EXPECT_FALSE(Some.contains(APInt(16, 0x0)));
   EXPECT_FALSE(Some.contains(APInt(16, 0x9)));
   EXPECT_TRUE(Some.contains(APInt(16, 0xa)));
@@ -73,7 +73,7 @@ TEST_F(ConstantRangeTest, Basics) {
 
   EXPECT_FALSE(Wrap.isFullSet());
   EXPECT_FALSE(Wrap.isEmptySet());
-  EXPECT_TRUE(Wrap.isUpperWrapped());
+  EXPECT_TRUE(Wrap.isWrappedSet());
   EXPECT_TRUE(Wrap.contains(APInt(16, 0x0)));
   EXPECT_TRUE(Wrap.contains(APInt(16, 0x9)));
   EXPECT_FALSE(Wrap.contains(APInt(16, 0xa)));
@@ -176,6 +176,29 @@ TEST_F(ConstantRangeTest, SignWrapped) {
   EXPECT_FALSE(ConstantRange(APInt(8, 250), APInt(8, 251)).isSignWrappedSet());
 }
 
+TEST_F(ConstantRangeTest, UpperWrapped) {
+  // The behavior here is the same as for isWrappedSet() / isSignWrappedSet().
+  EXPECT_FALSE(Full.isUpperWrapped());
+  EXPECT_FALSE(Empty.isUpperWrapped());
+  EXPECT_FALSE(One.isUpperWrapped());
+  EXPECT_FALSE(Some.isUpperWrapped());
+  EXPECT_TRUE(Wrap.isUpperWrapped());
+  EXPECT_FALSE(Full.isUpperSignWrapped());
+  EXPECT_FALSE(Empty.isUpperSignWrapped());
+  EXPECT_FALSE(One.isUpperSignWrapped());
+  EXPECT_FALSE(Some.isUpperSignWrapped());
+  EXPECT_TRUE(Wrap.isUpperSignWrapped());
+
+  // The behavior differs if Upper is the Min/SignedMin value.
+  ConstantRange CR1(APInt(8, 42), APInt::getMinValue(8));
+  EXPECT_FALSE(CR1.isWrappedSet());
+  EXPECT_TRUE(CR1.isUpperWrapped());
+
+  ConstantRange CR2(APInt(8, 42), APInt::getSignedMinValue(8));
+  EXPECT_FALSE(CR2.isSignWrappedSet());
+  EXPECT_TRUE(CR2.isUpperSignWrapped());
+}
+
 TEST_F(ConstantRangeTest, Trunc) {
   ConstantRange TFull = Full.truncate(10);
   ConstantRange TEmpty = Empty.truncate(10);